A conventional electrophotographic image forming device is provided with a photosensitive drum on which electrostatic latent images are formed, and a developing cartridge that develops the electrostatic latent images. The developing cartridge is formed with a toner accommodation chamber for accommodating toner. An agitator is provided within the toner accommodation chamber for agitating the toner therein. A window for detecting residual amounts of toner is formed in a side wall of the toner accommodating chamber, and the agitator is provided with a wiper for cleaning the window.
In this developing cartridge, the agitator is provided with a fixing member to which the wiper is fixed. Specifically, the fixing member includes a supporting plate and a clamping plate disposed in opposition to each other. The supporting plate is formed with a boss protruding toward the clamping plate. The wiper is formed of an elastic material such as a urethane rubber, and has an end portion formed with a through-hole corresponding to the boss. The wiper is inserted into a slit formed between the supporting plate and the clamping plate, and the boss is then inserted to penetrate the through-hole, thereby fixing the wiper to the fixing member.
For the sake of reducing costs in manufacturing the wiper, a resiliently deformable plate-like member made from a synthetic resin may be employed as a material, instead of an elastic material.
When an elastic material is employed as a material of the wiper, even though the through-hole has a diameter smaller than that of the boss, the diameter of the through-hole can be expanded so that the boss can penetrate the through-hole because of the elasticity. On the other hand, if a resiliently deformable plate-like member is used as a material of the wiper, the through-hole needs to have a greater diameter than the boss in order to enable the boss to reliably penetrate the through-hole. Therefore, the fixation between the resiliently deformable plate-like member and the fixing member may become loose, leading to lower positioning accuracy of the resiliently deformable plate-like member relative to the fixing member.